Tuesday, November 15, 2011

Our expensive cheap roads

On November 8, Gizmodo ran a great piece by Rachel Swaby about the deterioration of the American road system, much of it based on interviews with Tim Lomax of the Texas Transportation Institute. The roads were originally designed for private cars, with the expectation that most freight shipping would continue to be done by train. They were mostly constructed out of compacted dirt with a layer of asphalt on top, unlike the German Autobahn which was asphalt on concrete.

Truck freight offered a particular advantage over rail for shippers: on trains, small loads of a container car or two had to be decoupled from the train and possibly coupled to another train for the next leg of the journey. The more times a train had to be stopped in a yard, "broken" and reassembled, the longer the trip for the entire cargo.

A full truck, by contrast, could hold a lot less than a full train, but it could go directly from the loading point to the unloading point. Both freight railroads and road builders were surprised by the speed of the shift from rail to road. The roads were paid for by the government, and most of them were "free." Lomax tells Swaby that "companies are pushing the limits of what our roads can take, which increases their profits—but at the taxpayer's expense." It's clear to me that this has been going on for as long as there have been companies.

You probably know what happened next. The railroads began losing money, and cut their passenger service first. American housing and retail reorganized themselves around roads, and manufacturing and other industries followed. Faced with such intense demand for the roads, the federal, state and local governments embarked on a massive expansion plan. This just fed the appetite for more roads.

I've known for years about this vicious cycle of road subsidies, but I didn't make the connection with the use of dirt instead of concrete under the asphalt. It makes me wonder: if all these roads had been made with concrete, how much longer would it have taken to build out the 1950s era Interstate system? How many railroads would have avoided bankruptcy? How many downtowns would have been saved from being paved over for parking?

3 comments:

Yeah, their highways seem to be built to a much more highly-engineered level than ours are, designed with a more holistic approach. Their motorways amazingly seem to be flatter and have shallower curves, with fewer surprises popping up. American highways seem like they were designed 1000 feet at a time.

15 years ago, I saw electronic speed signage and special markers along the edge of highways in Germany that would light up in the event of an incident up ahead. That sort of thing has been slowly appearing here, but still nowhere near to the same extent as what I saw across the pond.

However, I think there's a big point that can undermine this argument -- European freight rail traffic is pretty minimal. Much of their freight moves by road too (though they still use waterways to move a lot of freight, something that is pretty minimal within the U.S.).

While you are absolutely correct in that the rail-road freight shift caused the decline of the great freight railroads, with the onset of containerization a substantial shift occurred in the American freight rail business. Our railroads are now our bulk freight transcontinental distribution network, due to containerization. In Europe, by contrast, maritime was always that, and only now are enough unification conditions (euro, Schengen, etc.) in play that a similar bulk distribution system can become viable. It's partly for this reason that European freight rail has been historically passenger-oriented (the other major reason: the carriers were all nationalized during the 20th century).

"They were mostly constructed out of compacted dirt with a layer of asphalt on top, unlike the German Autobahn which was asphalt on concrete."

Huh? I'm not a civil engineer and far from an expert, but I've watched road construction, and I always seem to see concrete poured onto big layers of rebar. Local DOTs only top coat with asphalt for maintenance if the underlying concrete foundation is still in good shape -- otherwise it's time to rip it all out and start over.

I suspect traffic volume is the bigger factor. 100,000 cars per day is considered a big number on the German Autobahn. I-5 through California only drops down below 100,000 vehicles per day when you get out into the lightly traveled rural portions of the Central Valley and northern California.